1. Field of the Invention
This invention relates in general to hot air balloons. The invention in particular relates to an improved venting process for the hot air used to control vertical ascent, descents and deflation of hot air balloons.
2. Description of the Prior Art
As hot air balloons have become more and more popular, they have been constructed with heaters beneath their lower opening so as to heat the air within the balloon envelope. It is necessary and desirable when the balloon lands to rapidly deflate the balloon so that the envelope will collapse, thus preventing it from being blown across the ground by the wind. It is also desirable to have a maneuvering vent for performing both vertical ascents and descents of the craft while in the air.
Prior art deflation ports provided openings which releases hot air from the top of the balloon envelope to deflate and/or maneuver the balloon vertically. Such deflation port systems which are used more than all others are called the “parachute” deflation port and vent systems. The parachute deflation port design consists of a circular opening located at the top or apes of the balloon envelope. In the deflation port opening are a plurality of load tapes which extend from the envelope gores over the center of the deflation port opening. A parachute is a circular piece of material which is made from the same fabric as the balloon envelope. The parachute is larger in diameter than the deflation port opening. The parachute is held in the envelope by a plurality of centering lines which are attached about the outer edge of the parachute. The opposite ends of the plurality of centering lines are attached to the envelope gore seams. When the balloon is inflated, with air, the internal air pressure pushes the parachute against the apex webbing so that the parachute seals the envelope about the edges of the deflation port opening. The parachute also has a plurality of shroud lines that are attached about the outer edges of the parachute at the same locations as the plurality of centering lines. The shroud lines do not attach to the balloon envelope. They extend down inside the envelope meeting directly below the parachute, where they are joined together and a pulley is attached to the shroud lines. A parachute deflation line has one end attached to an inside gore seam near the bottom of the balloon envelope and passes through the pulley. The other end of the deflation line extends downward passing through a second pulley. This is attached to the balloon envelope at a location which is opposite to the location of the deflation line termination point. The deflation line passes through the pulley and then extends down the balloon envelope and to the basket.
In operation, when the balloon is inflated, the internal pressure inside of the envelope pushes the parachute fabric against the apex webbing, thus sealing the deflation port opening. To release air for venting and/or deflation purposes the pilot in the basket pulls down on the deflation line, which pulls the deflation valve down and away from the apex webbing thus allowing air to escape the envelope. When the pilot releases the deflation port line, the internal pressure inside the envelope pushes the parachute up resealing the deflation port. Thus vertical control of the balloon in flight is accomplished. To terminate the flight, the pilot pulls down on the deflation port line holding it until the envelope deflates.